The field of the present invention is the manufacture of thin film transistors (TFTs).
Transparent electronics has attracted broad attention because of many of its promising commercial impacts since it can be used in many different applications such as solar cells, transparent displays and photodetectors. Ideal transparent electronics and displays are required to have high optical transparency, good electrical performance such as low power consumption and capability with diverse low cost substrates.
Table 1 undertakes a comparative study of various material systems used to implement TFTs. Metal oxides, amorphous silicon (a-Si) and low temperature polysilicon (LTPS) are possible candidates for transparent thin film transistors but high fabrication temperature and expensive vacuum and cleanroom facilities are required. Organic TFTs are also promising as they facilitate solution processing pathways; however, poor electrical performance such as high VTH and low mobility has hampered their progress. Single crystals polymers are emerging as desirable candidates, with solution processing capabilities and improved electrical performance. By comparing TFTs constructed on low temperature polysilicon, organic material, metal oxides and amorphous silicon with CNT TFTs, it is clear that the carbon based systems are the only candidates that offer transparency, flexibility, scalability, low temperature of fabrication and high mobility. Carbon based material such as CNT make it possible to conceive of a solution processing capability that offers dramatic cost benefits beyond existing vacuum-based TFT manufacturing methods.